Spinneyhill

I did not mean any criticism whatsoever. I was very thankful you brought the photos across. There are a few here and there, not many, but don't worry about it. I realise it is a lot of work. Frankly, your work is so absorbing I would rather you put the time into the restoration!

Sorry, this is nonsense. Modern engines, for which this was developed, contain magnesium, aluminium and similar metals and alloys right at the top of the galvanic series. They are very highly corrodible. Solder consists of metals further down the galvanic series. OAT antifreeze is safe with ALL metals. Read the bottle. Look up the web sites of makers.

I think you would be better to put anti-freeze or at least some anti-corrosion additive in the water and leave it in there. When you drain it, you are leaving it wet with humid air around - perfect galvanic corrosion conditions. You have Al plus Fe in close proximity with electrical connection through the water. Can you catch the leakage and pour it back in? You might want to use the latest technology too - OAT - because of the aluminium in there. Thank you for making the effort to bring the photos across from Photobucket. I wouldn't have been able to read this amazing thread, otherwise! Or your others. They are all very absorbing. You have far more patience in attempting to the things you do than I. What grease do you use in the steering box? Normally, NLGI 2 or similar is not very good because it is wiped off the worm on the first few turns and doesn't flow back. We use NLGI 00 semi-fluid grease.